Plant-Based Diet & Mood

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Speaking of chilling out, there’s a stereotype. The angry vegetarian. Who wants to eat healthy if it will just make you cranky? Well, a new study was just released on the emotional health and mood states of vegetarians. We know about the physical health benefits, but might that come at the cost of their mental health, particularly with regard to mood?

They used two psychological tests—what’s called a Profile of Mood States; looking at depression, anger, hostility, fatigue, confusion; and the Depression Anxiety Stress Scale, designed to measure negative mood states: hopelessness, lack of interest, anhedonia (which means lack of pleasure), anxiety, stress, agitation, irritability, and impatience with people.

What do you think they found? Fact or fiction: vegetarians tend to be, on average, more depressed, anxious, and sad. Fiction. Vegetarians report significantly less negative emotion than omnivores. Why, though?

They offer two explanations. First, if you’re unhealthy, I mean, if you’re sick all the time, going back and forth to doctors, dealing with HMOs—of course you’re going to be more irritable, stressed, and depressed. So, they suggest the emotional health of vegetarians may be in part a result of their superior physical health. The second reason may be arachidonic acid.

Arachidonic acid is metabolized in the body to produce inflammatory mediators. In fact, that’s how anti-inflammatory drugs like aspirin and ibuprofen work—by interfering with the conversion of arachidonic acid into compounds that produce inflammation, pain, and swelling.

Where is arachidonic acid found in our diet? Here’s a list of the top ten sources in the United States. Overwhelmingly, chicken and eggs, though there’s also some in beef, pork, fish, and other animal products.

So, maybe one reason vegetarians are, on average, so much happier, more positive, is that arachidonic acid is a key substrate for the synthesis of proinflammatory compounds in the body, which can adversely affect mood, mental health via a cascade of neuroinflammation. So omnivores may be more negative, depressed, stressed, hopeless, in part because their brains are so inflamed by their diet.

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